But to this day Yahweh hasn't given you a heart to understand or eyes to see or ears to hear.

I recently debated a Molinist on Facebook. Here's part of the exchange:

Toward the end of the book of Deuteronomy, God is speaking through Moses to every individual of Israel, and he says that the commandment is *not* too difficult for them to observe. They have a choice between alternatives, or else these passages are in error. It is impossible for God to lie, so those who want to affirm causal determinism would have to deny inerrancy to maintain their theology in light of these passages. Deut 29:4,10-15; 30:11-20.

i) You need to get beyond buzzwords like "causally determine" and define your nomenclature. How do you define causation? Do you employ a philosophical definition. How do you define determinism? 

ii) Your appeal to Deuteronomy is counterproductive to your thesis. In Deut 29:4, the text explicitly denies that the Israelites have the psychological aptitude to obey God. They are hard-hearted, spiritually deaf and blind. That's because, according to the text, God hasn't opened their hearts and eyes and ears. Their motivation to keep God's law depends on a spiritual condition that God hasn't granted them.

iii) Deut 30:11-14 refers, not to the ability to keep God's law, but the accessibility and intelligibility of God's law.

In order for God's words to each individual Israelite in Deuteronomy 30:11-20 to be true, then God must provide grace for them to be able to do it. Otherwise, either God is lying or inerrancy is false with regard to this text.

You're beginning with a preconceived notion, then using that as the yardstick. However, as I explained, the text doesn't say that God granted the Israelites enabling grace to keep his law. Indeed, the text says exactly the opposite! "But to this day Yahweh has not given you a heart to understand or eyes to see or ears to hear."

So your chosen prooftext doesn't illustrate your claim. To the contrary, it states the very thing you deny. 

You impugn God's word because it doesn't jive with your preconceived notion of what God ought to do. 

Certainly the text refers to the accessibility and intelligibility of God's law. But, I find it utterly implausible in the context for this passage not to also refer to the choice to keep God's law. There is no other way the Israelites could have understood God's words in this passage other than that they each actually can choose to obey the commandment. The very reason why God argues so forcefully through Moses that they can understand the commandment is to add to fact that each Israelite can also choose to obey it. No one in the audience can be excused for disobeying by claiming that they didn't understand.

You're not deriving your conclusion from the text. You haven't shown where the text itself says that or implies that. 

Rather, your conclusion is based on your assumption, extrinsic to the text, that it must include ability to comply. You merely stipulate that the Israelites must view matters the same way you do. That's not exegesis. 

Deuteronomy lays out consequences for obedience and disobedience. If you do A, then B will happen–but if you do C, then D will happen.

People can understand that without having the slightest inclination to act accordingly. 

Actually, you are reading too much into Deut. 29:4. This verse does not mean that in that moment God is not giving the Israelites a heart to understand. Instead, the portion translated as "to this day" in Deut. 29:4 means the same as "until this day".

Minimally, that involves a contrast between past and present. By "present," I mean at the time Moses is addressing Israel. That's at the end of the 40-year sojourn in the wilderness. Israel is about to embark on the conquest of the promised land.

So that stands in contrast to the last 40 years or so. Indeed, it could include the chilly reception which the Israelites gave to Moses when he returned to Egypt to deliver them.

So, according to that temporal marker, God hadn't granted them a heart and eyes and ears to comply for the last 40 years, in the wilderness. 

And, of course, God didn't originally give them the law on the eve of their entrance into the promised land. Rather, God gave them the law on their entrance to the Sinai desert, 40 years before. So, for the past 40 years, they've been lacking the divine enablement necessary to keep his law.

Yet according to you, that would either make God a liar or falsify Deuteronomy. So even if we concede, for the sake of argument, that moving forward, God will now grant them the grace they need to keep his law, that stands in contrast to God withholding such grace for the prior 40 years or so. Therefore, even if we accept your chronological distinction, for discussion purposes, it doesn't salvage your case. Rather, it simply relocates the problem, as you define the problem. 

Furthermore, the Deut 29:4 doesn't promise that God will open their hearts and eyes and ears in the future. It doesn't speak to that issue one way or the other. 

But, of course, the OT doesn't end with Deuteronomy. Is Israel more faithful in Joshua, Judges, Kings, Chronicles, Isaiah, Jeremiah, Ezekiel, &c.? 

Isn't Israel at least a faithless in the promised land as was the case in the wilderness? But if, according to you, Deut 29-30 marks a turning point, why is there no appreciable difference? Why is Israel just as bad or worse during the Conquest and occupation? 

Obviously, God is 'today' giving the Israelites hearts to understand as he says in Deut. 30:11-14.

That can't be obvious when Deut 3:11-14 doesn't actually say that.

Not at all. It seems obvious from the text that God means the Israelites can in fact comply and do what is commanded. Otherwise, how do you interpret the following verse?

That's fleshed out in the intervening verses. The law is not a secret law code. The law is not inscrutable. Rather, the law is available and comprehensible.

So they have the intellectual ability to keep the law, but that doesn't mean they have a heart to keep it. 

They are explicitly told to choose life…

They are told where their duty lies. They are told the divergent consequences of obedience and disobedience. 

But, you claim that God intends to [for?] them to understand that that they cannot possibly choose life.

No, I never claimed that God intends to communicate or intends for them to understand that they can't possibly choose life. Rather, I've said your prooftexts don't imply what you claim for them. And, indeed, Deut 29:4 says that right up until the present day, God withheld the enablement to do so. 

Incidentally, it's not an all-or-nothing proposition. It's not as if God must deal with Israel as an undifferentiated collective. God can open the hears and eyes and ears of some Israelites. It's not as though the only options are for God to either open no one's heart or open everyone's heart.